This invention relates to scuba diving apparatus, and more particularly to buoyancy control vests worn by scuba divers and an apparatus for control of the amount of air in such vests for adjusting the buoyancy of a scuba diver to meet various conditions which he encounters.
It has been common in the prior art to provide divers with vests having one or more inflatable reservoirs which may be inflated either by mouth, by using the diver's breathing air supply, or by another pressurized gas supply carried by the diver. Such vests are used for adjusting the buoyancy of the diver for various purposes. Initially, a diver may wish to swim on the water surface with the vest substantially inflated to lend positive buoyancy and thus facilitate such swimming. When the diver reaches a location where he wishes to submerge, he will at least partially deflate his buoyancy control vest, preferably to achieve either neutral buoyancy or negative buoyancy, possibly with the assistance of a weighted belt, until he has submerged to the depth at which he wishes to swim. He may then wish to reinflate his vest slightly to achieve neutral buoyancy. In some circumstances, the diver may need to adjust the amount of air in his buoyancy control vest as he changes the depth at which he is swimming in order to maintain neutral buoyancy.
It has been common in the prior art to utilize the diver's breathing air, available from a high pressure cylinder through a regulator which reduces the air pressure to less than 200 pounds per square inch. This air has typically been admitted by a special valve in the prior art, typically situated on the diver's chest. Alternatively, the prior art has permitted oral inflation of such vests.
The prior art has not, however, satisfactorily solved the problem of deflation of such vests. It has been common in the prior art to require a diver to open a valve directly venting the buoyancy vest to the surrounding water. The vest will, of course, not properly vent unless the tube leading from the vest to the vent valve is elevated to a position above the vest. Common procedure in the past has therefore been to have the diver roll on his back to position the vent tube at an elevation above the buoyancy control vest, or to detach the valve from a harness and raise it in his hand above the level of the vest. In this configuration, the pressure of the surrounding water will force air from the vest through the vent valve. This operation is clumsy, relatively slow, and in some circumstances may even be dangerous. It is possible, if the diver positions himself incorrectly, to flood the vest with water on opening of the vent valve. Furthermore, precise control of the amount of air within the vest is impossible using this technique and air from the breathing tanks is often wasted, since more air than is necessary for neutral buoyancy may be dumped from the vest requiring reinflation to achieve neutral buoyancy.
In addition, prior art vests typically include a safety valve which prohibits the vest from becoming overinflated, possibly rupturing the vest. These valves are generally located either on the vest or, in some instances, in combination with inflation valves, usually constructed as a completely independent valve structure, substantially increasing the cost of the vest or its valve assembly.
In the field of resuscitators, it has been common in the past to have quite complex mechanisms for resuscitating unconscious persons and animals and there has been not satisfactory small, extremely portable, relatively inexpensive device for this purpose.
Some resuscitators in the past have provided for pressurized air for inflating the lungs of an injured animal or person but have permitted the resilience of the animal's chest cavity to deflate the lungs before another pressurization cycle. Such a process is substantially slower and less effective for resuscitation than is a process where the animal's lungs are forcibly deflated by the resuscitating apparatus.